2. CONTENTS :
1. INTRODUCTION
2. DEMANDS FOR HIGH RISE BUILDING
3. MATERIAL
4. TYPES OF SYSTEMS
5. CONSTRUCTIONAL DETAILS
6. PRECAUTIONS
7. ADVANTAGES AND DISADVANTAGES
8. LIMITATIONS
3. WHATS IS HIGH RISE STRUCTURE ?
There are different definition for high rise construction.
-A high-rise building is one with four floors or more, or one 15
meters or more in height.
-Buildings between 75 feet and 491 feet (23 m to 150 m) high
are considered high-rise.
-Buildings taller than 492 feet (150 m) are classified as
skyscrapers.
4. Demands for high rise building
- Scarcity of land in urban area
- increasing demands for residential
and business space
- economical growth
- technological advancement
- innovation in structural system
- desire for aesthetic in urban setting
- concept of city skyline
- cultural significance and prestige
- human aspiration to build higher
5. Material
Cast
iron
Steel
R.C.C.
Glass
Cast iron :- Cast Iron use has been overtaken by Steel.
Cast Iron has little strength in tension but is very
strong in compression.
It can still be found in some older High Rise
buildings, usually to provide structural beams and
columns.
Glass :- Float glass with double glass is used in tall buildings .
Tempered glass is used in tall buildings instead of plain
glass, as that would shatter at such height.
TYPES OF MATERIAL
Aluminium
30 St Mary's Axe, London
PVC
6. Density : 2000Kg/m3
Thickness : 220mm
Weight/Square meter : 440 Kg/m2
Density : 2.51 g/c3
Thickness : 12mm
(Taking into account, a double glazed unit 6mm outer glass
- 12mm air gap - 6mm inner glass)
Weight/Square meter : 30kg/m2
So, considering a typical high rise building - 50 stories high
with 40,000m2 glass area
Estimated weight
reduction
: 16,400 Tons
GLASS BRICK WALL
GLASS
7. Ease in installation
When it comes to installation, following are the advantages of a
glass façade over a concrete one:
•Quicker fabrication & installation of glass façade
•In a single day of installation, a glass façade can cover 150 m2 in
comparison with brick wall 70 m2.
•Dry construction while using glass, which implies a cleaner project
site.
• Glass is 8 times lighter than a Brick wall facade!
• REINFORCED GLASS is a block which can withstand explosions,
even (to some extent) nuclear explosions.
• It is created by combining 7 Glass with 2 Advanced Alloy.
• Reinforced Glass is used in the creation of Irradiant Glass
Panes for Advanced Sola Panels as well as in the creation of
the Quantum Helmet.
Structural glazing for high rise
building:
•Aesthetics
•Signature designs
•Flexibility
•Robustness
Glass has a multitude of benefits :
Visual appeal
•Lightness
•Installation
•Customization
8. Steel :-
• Carbon is added and this acts as a hardener.
• Different mixes of steel will possess different characteristics
from varying hardness and malleability to Corrosion resistance
and weight.
• Its melting point is high at 1300C but it suffers from 3 key
failings under fire conditions.
• Loss of strength …. at 600C a steel beam may lose two thirds of
its strength.
• It is a good thermal conductor …. Meaning it can transfer its
heat to involve other materials not directly exposed to fire.
• It has a high thermal expansion….. at 500C a 10 Steel beam
can expand 60mm, if this beam was a structural
element within a building it may cause collapse.
• Because of its limitations in fire, if used in a structural context, steel
is usually given additional fire protection, in the form of a sacrificial
cladding or a barrier.
• The steel work buried within reinforced concrete is to a large degree
protected from fire by the concrete covering it.
9. • Aluminium is a relatively soft and light metal with a melting point of
660C.
• Its lightness means it has uses in the construction industry for non-
structural items, such as door and window frames and external
cladding.
• Aluminium’s greatest weaknesses is the low temperature at which
its structural stability is affected which can be as low as 100-250c,
and its high thermal expansion (over twice that of steel).
• where aluminium is used as a framing material it is important to
note that exposure to high temperatures will lead to early failure
and if these frames form part of the fire resistance of the building.
• Aluminium as an external cladding can melt if exposed to fire and
the falling molten aluminium possess additional hazards.
ALUMINIUM
Bank Of Hong Kong
10. P.V.C. (POLY VINYL CHLORIDE) -
•Unplasticised polyvinyl chloride is a lightweight is widely used as a framing
and cladding material.
•t is also extensively used in plumbing as pipe material for waste and rainwater.
•It is very durable but weak and like most plastics has a low decomposition
temperature (of around 220℃) and will liberate a large amount of acrid smoke.
•It has been extensively used in the refurbishment of many UK tower blocks
from the 60’s and 70’s to provide double glazed windows and balcony doors.
• Upvc does not burn freely and has class 1 fire rating but if exposed to fire it
will fail very early at an incident and, importantly to fire crews when used as a
framing material (especially external windows) this can lead to floor to floor
compromise.
11. REINFORCED CONCRETE
• A relatively modern addition to concrete has been fiber reinforcement. This can be
as a replacement to in addition to conventional steel reinforcement.
• Most large scale concrete construction in the world is now carried out using this
technique and the liquid concrete can be pumped or craned up buildings as
construction progresses.
• The concrete mixes used in this technique are formulated to an exacting standard
and the rebar is usually coated to protect it from corrosion.
• The failure of the concrete slab usually occurs in the form of spalling which is the
progressive deterioration of the surface exposed to heat.
• This is because the Aggregate element usually contain quartz which will start to
crack and disintegrate at 600C.
• It is the type and quantity of aggregate in the concrete mix that will define its
inherent fire resistance properties.
12. • Gravity loads
– Dead loads
– Live loads
– Snow loads
• Lateral loads
– Wind loads
– Seismic loads
• Special load cases
– Impact loads
– Blast loads
Seismic Loads
LOADS ON HIGH RISE BUILDING
13. Characteristics Of Wind
• Variation of wind velocity with height.
• Wind turbulence.
• Statistical Probability.
• Vortex shedding phenomenon.
• Dynamic nature of wind-structure interaction.
Types of wind
• Winds that are of interest in the
design of buildings can be classified
into 3 major types
- prevailing winds (trade winds)
-seasonal winds
-local winds
WINDS
Causes of Wind-
• Variation of Wind Velocity with Height-
Near the earth’s surface, the motion is
opposed, and the wind speed reduced, by
the surface friction.
•At the surface, the wind speed reduces
to zero and then begins to increase with
height
•Gradient Height 300 m for flat ground&
550 m for very rough terrain.
• How wind force governing for tall
structure with increase height of building?
•Construction cost per unit area decrease
•Increasing lightness in weight per unit
area
•More danger against high velocity of
wind force at high level.
14. •Wind load are always important for tall buildings ,which
form a vertical cantilever resisting the horizontal wind
pressure on one side and horizontal suction on the other
side.
•The building behaves like a horizontal
cantilevered beam resisting a vertical load; for a
high rise building the span of the cantilever is
much greater than any horizontal span in a
building.
15. Variation of wind velocity with height
-The viscosity of air reduces
its velocity adjacent to the
earth’s surface to almost
zero.
Wind behavior
16. TYPES OF SYSTEM
1. Shear wall System
2. Braced system
3. Hybrid System
4. Moment Resisting System
5. Trussed Tube
6. Bundled Frame Tube
7. Frame Tube
17. SHEAR WALL SYSTEM
• A type of rigid frame construction.
• The shear wall is in steel or concrete to provide greater
lateral rigidity.
• It is a wall where the entire material of the wall is
employed in the resistance of both horizontal and
vertical loads.
• Is composed of braced panels (or shear panels) to
counter the effects of lateral load acting on a structure.
• Wind & earthquake loads are the most common among
the loads.
• For skyscrapers, as the size of the structure increases,
so does the size of the supporting wall.
• Shear walls tend to be used only in conjunction with
other support systems.
18. BRACED SYSTEM
•Frame are cantilevered vertical trusses resisting laterals loads primarily
through the axial stiffness of the frame members.
•The effectiveness of the system, as characterized by a high ratio of stiffness to
material quantity, is recognized for multi- storey building in the low to mid
height range.
•Generally regarded as an exclusively steel system because the diagonal are
inevitably subjected to tension for or to the other directions of lateral loading.
•Able to produce a laterally very stiff structure for a minimum of additional
material, makes it an economical structural form for any height of buildings, up
to the very tallest.
19. KOBE COMMERCE
INDUSTRY AND TRADE CENTER,
KOBE,JAPAN
Architect : Nikken Sekkei ltd.
Structural engineer : Nikken Sekkei ltd.
Year of completion : 1968
Height : 110.06m
Number of stories : 26
Stories below ground: 2
Frame material : steel
Foundation condition : gravel and diluvial clay strata
Footing type: raft
Story ht. : 3.84m
Beam span : 9.45m
Beam depth : 600mm
Beam spacing : 3m
Material : steel grade 400mpa;concrete encased
structural steel 1st floor below
Slab: 160mm concrete on
metal deck
Columns:
At ground floor: 700mm x 700mm
Spacing: 3m
Material: steel grade 490 mpa
Core: structural steel with
prestressing bar
diagonal bracing
Kobe Commerce
Kobe , Japan
20. KOBE COMMERCE
• This building characterized by its tube in tube structure.
• Also consist of perimeter wall frames with 3m spans and internal braced frames
using prestressing steel bars for diagonal bracings.
• For purpose of efficiently increasing the earthquake resisting capacity of a
building ,it is preferable to design its structure in a bending failure mode so as
to disperse the yielding of frames during earthquake.
• Tube in tube structure in used for this.
• Braces has a wide elastic range and thus can resist the maximum seismic forces
within elastic region.
21. HYBRID SYSTEM
• Combination of two or more of basic structural forms either
by direct combination or by adopting different forms in
different parts of the structure.
HIGH
STRENGTH
CONRETE
STIFFNESS
DAMPING
OF
CONCRETE
ELEMENTS
LIGHTNESS
CONSTRUCT
ABILITY OF STEEL
FRAME
• Its lack of torsional stiffness
requires that additional
measures be taken, which
resulted in one bay vertical
exterior bracing and a number of
level of perimeter vierendeel
“bandages”
22. MOMENT RESISTING SYSTEM
• Definition and basic behavior of moment resisting
Frames
• Beam-to-column connections: before and after
Northridge
• Panel-zone behavior
• AISC seismic provisions for moment resisting
Frames: special, intermediate and ordinary
23. TRUSSED TUBE
• Interconnect all exterior columns to form a rigid box, which can resist lateral
shears by axial in its members rather than through flexure.
• Introducing a minimum number of diagonals on each façade and making the
diagonal intersect at the same point at the corner column.
• The system is tubular in that the fascia diagonals not only form a truss in the
plane, but also interact with the trusses on the perpendicular faces to affect the
tubular behavior.
• Relatively broad column spacing can resulted large clear spaces for windows, a
particular characteristic of steel buildings.
• The façade diagonalization serves to equalize the gravity loads of the exterior
columns that give a significant impact on the exterior architecture.
John Hancock Center
24. • The concept allows for wider
column spacing in the tubular
walls.
• The spacing which make it
possible to place interior frame
lines without seriously
compromising interior space
planning.
• The ability to modulate the cells
vertically can create a powerful
vocabulary for a variety of
dynamic shapes.
BUNDLED FRAME TUBE
Willis tower,
Chicago.
25. FRAMED TUBE
• The lateral resistant of the framed-tube structures is provided by very stiff
moment-resistant frames.
• The basic inefficiency of the frame system for reinforced concrete
buildings of more than 15 stories resulted in member proportions of
prohibitive size and structural material cost premium.
• The frames consist of 6-12 ft (2-4m) between centers, joined by deep
spandrel girders.
• Gravity loading is shared between the tube and interior column or walls.
• When lateral loading acts, the perimeter frame aligned in the direction of
loading acts as the “webs” of the massive tube of the cantilever, and those
normal to the direction of the loading act as the “flanges”.
• The tube form was developed originally for building of rectangular plan.
Dewitt Chestnut
26. Raft foundation: It is known for its load distributing capability.
• With the usage of this type of foundation the enormous load of the
building gets distributed & helps the building stay upright and
sturdy.
• Loads are transferred by raft into the ground.
Pile foundation: used for high rise construction.
• Load Of building is distributed to the ground with the help Of piles.
Transfer the loads into the ground with an Adequate factor of
safety.
Combined raft-pile: is the hybrid of 2 foundation.
• It Consists of both the pile and raft foundation.
• Useful in marshy sandy soil that has low bearing capacity.
FOUNDATION TYPES
28. Location and Height
Function :
• Function is one of the significant architectural parameters of tall buildings. As seen
in (Figure 4), mixed-use and office buildings are the two main types of function in
this type of building.
• Those are both around 77% of the total number of the tall buildings.
Base Plan :
• One of the important architectural factors representing the geometry and form of a
tall building is its base plan shape.
• This parameter is divided into six basic and simple shapes. These are rectangle,
ellipse and circle, curvilinear, triangle, polygon and parallelogram shapes.
• With these classifications, small variations in the base plan are not considered as a
separate group.
Form (based on aerodynamic and geometric characteristics :
• For form classification, different types of the aerodynamic (and geometric)
modifications used in tall buildings are considered..
ARCHITECTURAL CONSIDERATIONS
29. • Unprecedented heights and forces because of increased wind speeds and thus
forces through climate change now require designers to consider architectural
and structural strategies that will improve the efficiency of the design process
and of the building itself.
• The strategy of aerodynamic (geometric) modification is basically considered as
a precautionary and passive architectural concept to reduce the impact of
wind.
• The aerodynamic modifications can be divided into two main categories: macro
and micro.
• Macro modifications, such as tapering, setback and twisting, have basic effect
on the main geometry of the building whereas, micro modifications, such as
corner modifications, cannot affect the base form and shape of the building.
Structural Material :
• Selecting the structural material depends on such parameters as the function,
structural system, availability of material, and constructability.
• Using composite materials offers the advantages of both steel and concrete.
• Thus it is not surprising to find out that around 44% of all tall buildings are built
with composite materials and also to see that only %15 of the buildings used
steel
30. Diagrid system
• Diagrid system can be considered as a braced tube system without vertical
and horizontal structural elements.
• But, the aesthetic potential of the diagonal elements was not appreciated
since they were designed and constructed to obstruct the outdoor
viewing.
• Thus, diagonals were generally embedded within the building cores,
which were usually located in the interior of the building to be hidden
from the outside view.
• This system is recently used as a new aesthetic architectural-structural
concept for tall buildings .
• One of the visible differences between conventional exterior braced frame
system and current diagrid structures is that for diagrid structures almost
all the conventional vertical columns are eliminated because the diagonal
members in diagrid systems can continuously carry gravity as well as
lateral loads due to their triangulated configuration in the uniform
manner.
• This system in comparison with conventional framed tube system is much
more effective in minimizing shear deformation because the diagrid
system can carry shear by axial action of the diagonal members
COR Building, Miami
O-14 Building, Dubai
31. Advantages:
• Accommodates large number of families and business
houses.
• They reduce the distance to be travelled by occupants
saving their time.
• Permit more open space around the building.
• Provide more sunlight and pure air.
• Vertical expansion results in curtailment of cost of various
services such as water supply electrification.
• Saves land which can be used further.
• Pressure coefficients should need little adjustment for
different upwind terrain types .
• Existing meteorological data on wind gusts is used directly.
ADVANTAGES AND DISADVANTAGES
Disadvantages:
• Construction cost increases.
• Difficult for children and old people to go up when
elevators fails.
• Enjoying the charm of private garden cannot be
obtained.
• The approach is not suitable for very large
structures, or for those with significant dynamic
response.
• The response characteristics of the gust
anemometers and the natural variability of the
peak gusts tend to be incorporated into the wind
load estimates.